# US 10,370,321 B2 · Acetic acid recovery from wood acetylation > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,370,321 B2 - Document ID: US10370321B2 - Status: Granted - Kind: B2 - Application number: 15/326,675 - Filed: 2015-07-17 - Published: 2017-07-20 - Granted: 2019-08-06 - Earliest claimed: 2014-07-18 - Assignees: Tricoya Technologies Ltd - Applicants: Tricoya Technologies Ltd - Inventors: Benjamin Thomas Painter; Stephen John Benstead - Web page: https://patentgrep.com/patent/US10370321B2 ## CPC - C07C 51/46: by azeotropic distillation - B01D 3/14: Fractional distillation {or use of a fractionation or rectification column} - B01J 19/245: {placed in series} - C07C 51/44: by distillation - C07C 51/56: from organic acids, their salts, their esters {or their halides, e.g. by carboxylation} - C08B 3/06: Cellulose acetate {, e.g. mono-acetate, di-acetate or tri-acetate} - C08H 8/00: Macromolecular compounds derived from lignocellulosic materials {(pretreatment thereof B27N)} - B01J 2219/24: Stationary reactors without moving elements inside - B27K 3/346: {Grafting onto wood fibres (B27K3/156 takes precedence; macromolecular compounds derived from lignocellulosic materials C08H)} - Y02E 50/10: Biofuels, e.g. bio-diesel - C07C: ACYCLIC OR CARBOCYCLIC COMPOUNDS - B01D: SEPARATION (separating solids from solids by wet methods B03B, B03D; by pneumatic jigs or tables B03B; by other dry methods B07; magnetic or electrostatic separation of solid materials from solid materials or fluids, separation by high-voltage electric fields B03C; centrifuges, vortex apparatus B04; presses per se for squeezing-out liquid from liquid-containing material B30B9/02; treatment of water C02F, e.g. softening by ion-exchange C02F1/42; {arrangements of air intake cleaners in gas turbine plants F02C7/05} ; arrangements or mounting of filters in air-conditioning, air-humidification or ventilation F24F13/28) - B01J: CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS - C08B: POLYSACCHARIDES; DERIVATIVES THEREOF (polysaccharides containing less than six saccharide radicals attached to each other by glycosidic linkages C07H; fermentation or enzyme-using processes C12P19/00; sugar industry C13; production of cellulose D21) - C08H: DERIVATIVES OF NATURAL MACROMOLECULAR COMPOUNDS (polysaccharides C08B; natural rubber C08C; natural resins or their derivatives C09F; bituminous materials C10) - B27K: PROCESSES, APPARATUS OR SELECTION OF SUBSTANCES FOR IMPREGNATING, STAINING, DYEING, BLEACHING OF WOOD OR SIMILAR MATERIALS, OR TREATING OF WOOD OR SIMILAR MATERIALS WITH PERMEANT LIQUIDS, NOT OTHERWISE PROVIDED FOR (applying liquids or other fluent materials to surfaces in general B05; coating wood or similar material B44D); CHEMICAL OR PHYSICAL TREATMENT OF CORK, CANE, REED, STRAW OR SIMILAR MATERIALS - Y02E: REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION ## Abstract Disclosed is the integration of the production of acetic anhydride from ketene, and the acetylation of wood using acetylation fluid comprising acetic acid and acetic anhydride. The invention involves combining acetic acid obtained from distillation of acetylation fluid with a residual aqueous acetic acid stream as obtained from ketene production. ## Claims ### Claim 1 A process for the purification of acetic acid recovered from a wood acetylation process, wherein wood acetylation fluid comprising acetic acid and acetic anhydride obtained from a wood acetylation process is subjected to acetic acid recovery by distillation, and wherein acetic acid thereby recovered is mixed in a treatment section with a residual aqueous acetic acid stream from a unit for the production of ketene from acetic acid, and the resulting mixture is directly subjected to distillation so as to produce purified acetic acid. ### Claim 2 (depends on 1) A process according to claim 1, wherein the purified acetic acid is used as a reactant feed to the unit for the production of ketene. ### Claim 3 (depends on 2) A process according to claim 2, wherein produced ketene is subjected to reaction with acetic acid in a unit for the production of acetic anhydride, thereby producing acetic anhydride, said acetic anhydride being used as an acetylation fluid in said wood acetylation process. ### Claim 4 (depends on 3) A process according to claim 3, wherein the purified acetic acid is used as a reactant feed to the unit for the production of acetic anhydride. ### Claim 5 (depends on 1) A process according to claim 1, wherein produced ketene is subjected to reaction with acetic acid in a unit for the production of acetic anhydride, thereby producing acetic anhydride, said acetic anhydride being used as an acetylation fluid in said wood acetylation process. ### Claim 6 (depends on 5) A process according to claim 5, wherein the purified acetic acid is used as a reactant feed to the unit for the production of acetic anhydride. ### Claim 7 (depends on 1) A process according to claim 1, wherein the produced acetic anhydride is subjected to a concentration increase by distilling off acetic acid in a raw anhydride distillation unit, before being used in the wood acetylation process. ### Claim 8 (depends on 7) A process according to claim 7, wherein the acetic acid recovery from the wood acetylation fluid is conducted by distillation in the raw anhydride distillation unit. ### Claim 9 (depends on 1) A process according to claim 1, wherein the ketene produced in the unit for the production of ketene is fed as a reactant to the unit for the production of acetic anhydride. ### Claim 10 A system comprising a wood acetylation section, a ketene production unit and a treatment section, wherein the treatment section is configured for the recovery of acetic acid from a residual aqueous acetic acid stream, the system comprising a separation section for the separation of acetic acid obtained from the wood acetylation unit, said separation section being in fluid communication with said treatment section, and wherein said treatment section comprises a distillation unit. ### Claim 11 (depends on 10) A system according to claim 10, wherein the ketene production unit is comprised in a section for the production of acetic anhydride, said section comprising the ketene production unit and, downstream thereof, an acetic anhydride production unit. ### Claim 12 (depends on 10) A system according to claim 10, which further comprises an acetic anhydride production unit. ### Claim 13 (depends on 10) A system according to claim 10, wherein the ketene production unit comprises a ketene furnace. ### Claim 14 (depends on 13) A system according to claim 13, wherein the ketene furnace has an outlet connected to a cooler, wherein the cooler is configured to separate produced ketene from residual aqueous acetic acid, and wherein the cooler has an outlet for produced ketene to the acetic anhydride production unit and an outlet for residual aqueous acetic acid to the distillation unit comprises in the treatment section. ### Claim 15 (depends on 8) A system according to claim 8, wherein the distillation unit of the treatment section is configured to also receive acetic acid from the separation section.